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Wide Racial Disparities Found in Coronary Artery Disease Deaths

By Duke Medicine News and Communications

DURHAM, N.C. -- African-American patients with coronary
artery disease die at a significantly higher rate than white
patients with the same degree of disease, according to an
analysis of more than 20,000 patients by cardiologists at the
Duke Clinical Research
Institute.

Among patients diagnosed with serious coronary disease who
were followed for an average nine years, the researchers found
that blacks have had a 36 percent survival rate while whites
have had a 46 percent survival rate.

The researchers said the disparity can be partially by the
findings that blacks tend to have higher rates of other medical
conditions, which can complicate or contribute to heart
problems, and that blacks do not receive coronary artery bypass
surgery as often. But the researchers stressed that other
unproven factors almost certainly are involved and that further
research is needed to identify them and quantify their
contributions.

"As prevention becomes a key point of emphasis in treating
heart disease, it is vitally important to identify risk factors
and to act on them," said cardiology fellow Kevin Thomas, M.D.,
who reported the results of the analysis on Sunday, Nov. 12, at
the annual scientific sessions of the American Heart
Association, in Chicago.

The study was supported by a young investigator award from
the Association of Black Cardiologists and the Duke Clinical
Research Institute.

"Past studies from which risk factors have been derived
provide great information about heart disease in white men, but
the studies have included few minorities and women," Thomas
said. "Cardiovascular disease is the leading cause of death for
blacks and whites in the United States, and yet there is a
paucity of information on the long-term prognosis for
blacks."

For the analysis, Thomas and colleagues consulted the Duke
Database for Cardiovascular Disease, a compilation of data on
heart patients who come to Duke University Medical Center for
diagnosis and treatment. The team analyzed the outcomes of
21,054 patients seen between 1986 and 2004 and found to have
serious coronary artery disease. Of those patients, 3,177 were
black.

In general, the black patients tended to be younger and more
often female, and they had higher rates of hypertension,
diabetes, heart failure or previous heart attacks, Thomas said.
After the team statistically accounted for those patient
characteristics, the disparity in death rates persisted, Thomas
said, meaning that other factors must be contributing to the
disparity.

"When we looked at the extent of coronary disease, we found
there was little difference between blacks and whites," Thomas
said. "However, when we looked at the incidence of procedures
received by patients within 30 days of cardiac catheterization,
we found that whites were 12 percent more likely to receive
coronary bypass surgery."

According to Thomas, it is not clear why blacks did not
receive coronary bypass surgery as often as whites. One
possible explanation, he suggested, is that some physicians may
have been biased against blacks, whether intentionally or not,
as has been shown in past Duke studies. He also said that many
blacks have a historical mistrust of the medical system, and so
black patients might not have been as willing to undergo
coronary bypass surgery, an invasive procedure.

"A big part of that mistrust is communication," Thomas said.
"If black patients don't have a complete understanding of the
procedure, or if it is not explained well, they may decline the
procedure. If a physician or health care provider explains the
procedure and what it entails, more black patients might agree
to the surgery -- especially if the person doing the explaining
were black or trained to be culturally sensitive."

Aside from less use of bypass surgery, other factors also
likely contributed to the observed disparities and need to be
investigated in future studies, Thomas said.

For example, he noted that heart patients typically receive
optimal care while they remain in the hospital.

"However, when patients return to their home environment,
they face many challenges and barriers to following their
doctor's advice and maintaining a healthy lifestyle," he said.
"Patients may not fill their prescriptions, or if they do, they
may not take the medication over the long term. Often, patients
may revert to bad habits in terms of diet and smoking. They may
not return for follow-up doctor visits or they may not have
doctors that they see regularly. These obstacles may
disproportionately affect minority populations."

To learn more about what treatments work best for individual
patients, Thomas said, the medical community should mount
concerted efforts to attract more blacks into participating in
clinical trials.

"There has been a history in the black community of mistrust
of the health care system, which has often been seen as using
blacks in medical experiments," Thomas said. "To overcome this
mistrust, we must learn how to communicate in a culturally
sensitive manner. Not all people are the same, so you have to
tailor your communication to your patient if you want to
improve outcomes."

He said the Association of Black Cardiologists, which is
respected and trusted in the black community, is working in
various ways to improve the levels of minority enrollment in
clinical trials of heart therapies.

Also, he said he expects that results from the current
Jackson Heart Study, a National Institute of Health supported
study which is focusing on cardiovascular disease among the
black residents in and around Jackson, Miss., will yield
important data. This study, he said, may provide advances in
the manner of the classic Framingham Heart Study, which began
in 1948 and still continues, though it focuses primarily on
white men.

Other researchers who participated in the Duke analysis were
Emily Honeycutt, Linda Shaw and Eric Peterson.